In a New York Times interview:
I would meet directly with Syrian leaders. We would engage in a level of aggressive personal diplomacy in which a whole host of issues are on the table…but right now the only incentive that exists is our president suggesting that if you do what we tell you, we may not blow you up. My belief about the regional powers in the Middle East is that they don’t respond well to that kind of bluster. They haven’t in the past, there’s no reason to think they will in the future.
English 
Spanish 